1. Technical Field of the Invention
The present invention relates to a plastic container having foldable side walls with a pivotal structure disposed at each side of a bottom wall capable of forming a box-shaped container with an open top by erecting each side wall, and also capable of being folded when not in use.
2. Background Art
Plastics play an indispensable role in a wide variety of markets, including packaging, building, construction, transportation, consumer and institutional products, furniture and furnishings, electrical/electronic components, adhesives, inks and coatings. The plastics industry is also one of the largest manufacturing industries in the world.
With respect to packaging, plastics provide advantages that are not otherwise possible with traditional materials. Different plastics offer different qualities, giving manufacturers and consumers the freedom to choose the type of plastic that best suits the application. Plastics can be rigid when protection is needed, or flexible for other applications. The plastic packaging can be clear, opaque, or any color. And it can be molded into a wide variety of shapes and sizes.
In medical facilities, plastic packaging offers a superior ability to protect products against contamination. The chemical resistance properties, transparency and toughness of plastics enhance safety and efficiency in both the laboratory and day-to-day hospital use. Plastics, which can conform to any shape and guard against impurities, are the perfect materials for shipping and storing intricate medical instruments. And in uses such as see-through and break-resistant containers, plastic packaging has proven indispensable in modern medical care.
For home use, the break-resistant, shatterproof and sturdy plastic packaging reduces both injuries and cleaning by providing an easy product to use for storing detergents, cleaning agents and similar goods. Food-service outlets and their customers rely on plastic packaging to protect food products against contamination and retain desired temperatures longer during transport.
The use of plastics and plastic containers for shipping and storage is rapidly growing. Strong, durable and cost effective, plastic assemblies saves energy, space and money. Plastic containers generally require less energy to manufacture than other packaging, require less fuel to transport than heavier counterparts, and occupy less volume for shipping and storage than traditional products. There are further reductions in shipping damage and elimination of the need for additional packing materials, such as partitions between individual products. Strong enough for stacking and moldable into space-saving shapes, plastic containers maximize transport space, and warehouse room.
Plastic containers can also meet unique packaging concerns including anti-static protective properties, thermal stable packaging, and anti-bacterial and anti-microbial properties in the packaging. The container can be molded to fit contours and spacing requirements to provide the ultimate protection in packaging office machines, entertainment units, computer components and other delicate products. These plastic package products are tough enough to withstand the stresses of transportation yet capable of screening out dust and dirt.
Another benefit of plastic containers is that they can be adapted to other uses to reduce waste in landfills and satisfying needs in other markets. And, recycled plastics provide an even further incentive to use plastics for packaging, with the recycled materials are used to create new products. The safe, sanitary, easy to use and economical, plastic packaging is the preferred choice for many.
A particularly useful packaging system is a collapsible container. Rigid containers occupy too much space and are difficult to work with when stacked. The collapsible containers found in the prior art are prepared with side attachment walls free from a bottom wall and attached to a bottom wall with a hinge on each side of a bottom wall. The container can be assembled by attaching side walls to the bottom wall. A side attachment wall is connected to a bottom wall, and the collapsible structure is assembled into a container by unfolding the sidewalls to extend approximately perpendicular to the bottom wall.
The collapsible container indicated in Japanese Patent JP 06-42657 contains side attachment walls that hinge onto the bottom wall. The method of making the container walls results in a burr on the metal mold, and suffers from a low luminous efficacy rate of effective resin, and a metal mold size that is large. U.S. Pat. No. 4,615,464 describes a molded container case comprising a cover and a base with a hinged connector pivotably joining the cover and the base.
The prior art also describes a container for storing or transporting articles, wherein the container has side walls interconnected to the bottom wall and assembled by erecting the side walls. Such an article is shown, for example, in Japanese Patent Application Laid-Open No. 63-82941 or JP-A No. 2958339. In this type of assembly type container, the foldable side walls are provided on each side of the bottom wall by way of thin hinges, and adjacent side walls are mutually engaged to set up the container.
In the assembly type container disclosed in JP-A No. 63-82941 or JP-A No. 2958339, as the container is disassembled, the side walls are spread flat around the bottom wall of the container, but it is bulky and difficult to stow away, store or carry. In addition, the side walls are linked to the bottom wall by the thin hinges, and if a load is applied to the side walls in the downward direction, the load is borne by the thin hinges, and more easily broken.
Another container for storage and transportation is disclosed in JP-A No. 10-101066 and JP-A No. 10-101067. These devices by the present inventor has foldable side walls provided on each side of the bottom wall through hinges of a pivotal structure, and the container is set up by erecting and mutually engaging the adjacent side walls. The container disclosed in JP-A No. 10-101066 and JP-A No. 10-101067, provides for convenient stowing since the side walls can be folded to be parallel to the bottom wall. The folded container is therefore convenient for stowing, storing or carrying. And, since the side walls are linked to the bottom wall by hinges of a pivotal structure, if a load is applied to the side walls in the downward direction, the hinges are rarely broken. This is particularly important when stacking the containers.
Despite the advantages of the prior art container design, these designs lack a mechanism for holding the side walls securely in the upright position. For example, the container side walls tend to collapse in the process of fastening the mutually adjacent upright side walls. This prior art container design is therefore difficult for one person to assemble and requires more time in forming the container. Although the prior art has attempted to manufacture an efficient container assembly, there is considerable room for improving the ergonomic assembly by improving the design.